Question: Range of Variable Expressions

Comment on Range of Variable Expressions

this problem belongs to magoosh but why you upload here? IT"S not fair
greenlight-admin's picture

I can assure you that I'm the creator and copyright owner of this video.

If you have any doubts, you can contact Magoosh about it.

Cheers,
Brent

Now, why would you have to multiply again by 2 after we eliminated 2 from the second to last step?
greenlight-admin's picture

Earlier in the question, we concluded that the range = 2x + 2y

So, once we know that x+y = 20, we must multiply both sides by 2 to get: 2x + 2y = 40

Does that help?

Cheers,
Brent

Hi,
Plz let me know if I can put values:

As the median is : x + y = 20
let x = 1 and y = 19 , 0 < x < y or 0 < 1 < 19

Now x - y = -18

and 3x + y = 22

The range from -18 to 22 = 22 - (-18) = 40

Thanks
greenlight-admin's picture

Perfect!
Once we know that the median = 10, we can just plug in values for x and y to determine the range.
Cheers,
Brent

Whoops.
Not *quite* perfect. :)
You probably didn't catch the arithmetic mistake.

@useradb9cc chose suitable numbers. (Any two numbers for x and y that sum to 20 will work.)

In that post, as correctly noted, x=1, y=19, and
x-y= -18
3x+y= 22

But the range of -18 and 22 does not equal 41.

The range is
22-(-18) = (22+18) = 40
(not 41)


@useradb9cc
greenlight-admin's picture

Good catch - thanks!!
I edited useradb9cc's solution (to help minimize confusion)!
Thanks again!

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